It is well known to use oils to deliver a skin feel benefit. For example it has been known since antiquity to add oil to bathwater so as to obtain a benefit, by deposition of a portion of the oil onto the skin. It is also known to prepare compositions which contain both one or more oils and a surfactant so as to form an emulsion on dilution with bathwater.
Over the past few decades, for reasons of economy, showers have become increasingly popular and so-called `shower gels` have become increasingly popular as washing compositions. Shower gels generally differ from bath additives in that they have a higher viscosity, due to the presence of higher levels of thickening surfactant systems and electrolytes. The high viscosity of shower gels is necessary to prevent the composition being washed off the skin before a foam can be developed and soil can be solubilised.
It is known to include oils in shower-gel formulations, these oils have been selected from relatively high molecular weight oils such as silicone oil and relatively low molecular weight oils such as mineral oils and oily esters such as isopropyl palmitate and myristate. In the context of the present invention a low molecular weight oil is one with a molecular weight below 4000.
Isopropyl palmitate and myristate are known and used as moisturisers in skin products such as hand creams and the like. Hand creams are non-foaming, highly thickened compositions which can comprise a lamellar phase of surfactant or which employ other thickening agents incompatible with foaming surfactants.
In shower gels, only low levels of the above-mentioned low molecular weight oils have been employed, as higher levels of these oils are incompatible with the foaming surfactants generally employed.
It is believed that the levels of relatively low molecular weight, moisturising oils present in known shower-gel compositions are insufficient to achieve the desired skin-benefits.
The technical problem faced by the present invention, is therefore to provide a foaming composition having a viscosity suitable for use as a shower-gel, which contains an effective level of low molecular weight moisturising oil and which does not lose product structure due to the presence of this oil.